Tweeters distorting during explosions

[pmanicioto]

I just rearranged some things over the last couple days with my setup and happened to find a Lucas demo disc for DTS and DD testing.

I ran through one of the demos where it shows some star wars tie fighter scenes. In the one scene there is an explosion that I can hear through my tweeters in my KF26's up front.

I thought I heard this before on some other discs when tons of explosions and action was going on, but thought it was my imagination.

Any idea why this is happening? Are the tweeters just not handling the load? Or are too low of frequencies getting to them somehow? I was under the assumption they were internally crossed over inside the cabinet?

I tried biamping them to see if that would help and did not.

Setup consists of KF26's up front, KC25 for center and KS14's I just got for the surrounds this week. Denon 1912 for power

All crossed over at 80hz. I set to 120 also to test and still same issue.

Audessy actually set them all to large and crossed over to like 40-60hz, but I set them back to small and 80hz as per some other research I did explaining to let the sub do most of the work.

Any ideas?

[WMcD]

I've heard some ticking noises out of my Forte II with some Mahler symphonies. Also my home made Belles with the Telarc recording of T-Rex and others. The ones with warnings.

My solution has always been the volume control.

It seems that big bass is getting into something. My guess is that the bass unit of your speaker is bottoming out. Woofers make some treble type sounds when this happens, I think.

If you can disconnect the treble unit you might be able to eliminate the treble unit as a source and then you know something.

I hesitate to recommend even that because the noise shows that something is very unhappy and getting close to destruction.

WMcD

[formica]

Yes, they do have a crossover on the inside. I can think of several possibilities.

You may be over driving them... I'm not sure of your reciever's power rating nor the volume you are listing to it, but you may be clipping the amp, sending distortion to the tweeter. This can also be accentuated if you reciever has a room correction that has boosted high frequencies.

I'd also look for any loose connections... it is possible that the bass is shaking one of those connectors. I've had it happen to to a tweeter connector at the crossover on a Khorn. Unfortunately I'm not sure of the crossover location on the KF26's, but it may be installed behind speaker connectors (on the inside of the cabinet).

Good luck.. ROb

[pmanicioto]

Could it be due to the woofers pushing too much air in the cabin and bottoming out the tweeters?

I'm almost positive it's not a loose connection and fairly positive it is th tweets making the noises.

I have listened to other items much higher volume. Maybe the quality of that part of the demo wasn't the greatest?

[derrickdj1]

Those speakers came out in 2011, so they should still be under warranty. I have a feeling you stressed something due to amp clipping. What amp/avr are you using and have you raised the levels of the auto/room correction?

[moray james]

This is a very good observation and will possibly eliminate the tweeter as a cause of the distortion. you could also disconnect the woofers and play the same track at the same level and see if the tweeter alone is the cause of your problem. Larger loudspeakers and larger amlifiers are always a wise choice and now you can see why, Sharp thinking William. Best regards Moray James.

[pmanicioto]

I will try disconnecting the jumpers tonight and run just the tweeter to see how they respond.

As far as levels, yes I have run the levels up a bit from the room correction since I got them and just ran at lower volume. I now have them at the audessy settings and higher volume to compensate.

I don't hear it all the time at that volume, just during certain scenes with explosions.

Avr is a Denon avr-1912. Rated at 90w per channel.

Only real changes recently were moving the towers outward and toeing in a bit and upgraded the surrounds and the. Ran Audessy again to recalibrate and left at those settings and just bumped the center level a little

[WMcD]

I see that the fronts (sides) have dual inputs to allow bi-wiring or bi-amping. So it is not difficult to disconnect the tweeter (or woofer) and the internal crossovers are still in place.

OTOH, from what I see, the center just has a regular one terminal input. So you can't fool with it too much. Certainly do not run the tweeter without the internal crossover.

I see the center is a sealed box. Those types do have mechanical resonance which allows the bass diaphragms to move quite easily at resonance. If you see photos of bass speakers with pulsing bass where the diaphragm is going through wild excursions, that is the freq. It looks dramatic but dangerous to the unit. As you go lower, the sealed box controls motion 'cause the air in the box has to be compressed.

The fronts (sides) are ported. Here the resonant freq is at or near the resonance of the port-box combination. The diaphragm is loaded by this. So there is not a problem with bottoming out near the resonance. But if you go lower, the box-port is not loading the diaphragm and thus you can have bottoming out.

Overall, I want to warn about hitting these small speakers with a lot of bass. Special effect recordings provide a lot more than older pop music. If you can, it might be worthwhile to set the roll over to the sub (on your receiver) as high as possible, Can you set it to 120 Hz?

WMcD.

[pmanicioto]

I contacted klipsch and they feel I am underpowering the fronts.

Anyway I set the crossovers to 120hz to try now to see if that helps.

I don't think it is the woofers. I'm pretty positive it's the horns.

They said the underpowering is causing distortion at higher volumes. This is my third receiver in like 6 months. Lol. I'm out of money to get a new one again.

[mustang guy]

I contacted klipsch and they feel I am underpowering the fronts.

Anyway I set the crossovers to 120hz to try now to see if that helps.

I don't think it is the woofers. I'm pretty positive it's the horns.

They said the underpowering is causing distortion at higher volumes. This is my third receiver in like 6 months. Lol. I'm out of money to get a new one again.

Perhaps you should invest in a decent amplifier, and use the pre-outs on your receiver, if it has them.

edit: Never mind, I see your Denon 1912 does not have pre-outs.

[DavidF]

Take the system down to basic two channel. Especially go around the room correction equalization. No subs, etc. See if the sound clears up. I would think that the amp section is breaking up for lack of power/current reserves.

[derrickdj1]

I contacted klipsch and they feel I am underpowering the fronts

I had an Icon V ht and had the VF 35 as front speakers power by a Sony 100 watt avr. Things were pretty good as long as I did not push the amp to hard. When pushed, noticeable tweeter/bass distortion with what I thought was underpower of the bass and overpower of the tweeter. Long story on the short, I got another avr. No further problems with my Icon speakers. I xo my Icon speakers at 100 for the center, surrounds and towers due the surround speaker LF extension of 89. For you, 80 or 100 will work: use 100 and let the sub do some work, not much difference between 80 and 100.